U.S. patent application number 10/660750 was filed with the patent office on 2004-10-28 for apparatus for recognizing an image.
Invention is credited to Choi, Beohm-Rock, Choi, Joon-Hoo, Joo, In-Soo, Yang, Sung-Hoon.
Application Number | 20040213440 10/660750 |
Document ID | / |
Family ID | 33297352 |
Filed Date | 2004-10-28 |
United States Patent
Application |
20040213440 |
Kind Code |
A1 |
Joo, In-Soo ; et
al. |
October 28, 2004 |
Apparatus for recognizing an image
Abstract
In a fingerprint recognition apparatus, a first recognition
section is formed on a center portion of a transparent substrate
and a second recognition section is formed on the transparent
substrate adjacent to the first recognition section. The first
recognition section recognizes an image pattern from an object
making contact with the transparent substrate to generate a first
recognition signal and the second recognition section senses a
biological signal so as to check whether or not the first
recognition signal is obtained from a human being. Accordingly, the
fingerprint recognition apparatus may check that whether or not the
object having the image pattern is obtained from a human being,
thereby recognizing the image pattern with high accuracy and
improving reliability thereof.
Inventors: |
Joo, In-Soo; (Seongnam-si,
KR) ; Choi, Joon-Hoo; (Seoul, KR) ; Yang,
Sung-Hoon; (Seoul, KR) ; Choi, Beohm-Rock;
(Seoul, KR) |
Correspondence
Address: |
McGuireWoods
Suite 1800
1750 Tysons Boulevard
McLean
VA
22102-4215
US
|
Family ID: |
33297352 |
Appl. No.: |
10/660750 |
Filed: |
September 12, 2003 |
Current U.S.
Class: |
382/124 |
Current CPC
Class: |
G06V 40/1306 20220101;
G06V 40/40 20220101 |
Class at
Publication: |
382/124 |
International
Class: |
G06K 009/00 |
Foreign Application Data
Date |
Code |
Application Number |
Apr 25, 2003 |
KR |
2003-26247 |
Claims
What is claimed is:
1. An image recognition apparatus comprising: a transparent
substrate; a first recognition section disposed on the transparent
substrate, the first recognition section receiving an image pattern
from an object and generating a first recognition signal
corresponding to the received image pattern; and a second
recognition section disposed on the transparent substrate adjacent
to the first recognition section, the second recognition section
sensing a biological signal from the object so as to check whether
or not the first recognition signal is obtained from a human
being.
2. The apparatus of claim 1, wherein the first recognition section
is disposed on a center portion of the transparent substrate and
the second recognition section is disposed on a peripheral area
surrounding the first recognition section.
3. The apparatus of claim 2, wherein the first recognition section
comprises an image recognition sensor that generates the first
recognition signal corresponding to an amount of a reflecting light
reflected from the image pattern, the amount of the reflecting
light being differently reflected according to a position from
which the reflecting light is reflected.
4. The apparatus of claim 3, wherein the image recognition sensor
comprises: a sensing TFT that outputs a voltage signal
corresponding to the reflecting light reflected from the image
pattern; a storage capacitor that charges an electron charge
corresponding to the voltage signal input from the sensing TFT; and
a switching TFT that outputs a voltage signal corresponding to the
electron charge charged into the storage capacitor in response to a
switching signal applied from an external.
5. The apparatus of claim 2, wherein the second recognition section
comprises: a first biological-signal recognition section disposed
on a first end portion of the transparent substrate, which is
adjacent to the first recognition section; and a second
biological-signal recognition section disposed on a second end
portion of the transparent substrate, which is adjacent to the
first recognition section and opposite to the first end
portion.
6. The apparatus of claim 5, wherein the first and second
biological-signal recognition sections comprise a capacitance type
biological-signal recognition sensor that acts as a capacitor with
the object having the image pattern.
7. The apparatus of claim 6, wherein the first and second
biological-signal recognition sections act as a lower electrode of
the capacitor and the object having the image pattern acts as an
upper electrode of the capacitor.
8. The apparatus of claim 7, wherein the biological-signal
recognition sensor comprises: a first TFT that outputs a
predetermined voltage signal; a conductive sensing electrode that
acts as the capacitor with the upper electrode, the conductive
sensing electrode charging an electron charge corresponding to the
predetermined voltage signal from the first TFT; and a second TFT
that outputs a voltage signal corresponding to the electron charge
charged into the conductive sensing electrode.
9. The apparatus of claim 1, wherein the image pattern of the
object comprises a fingerprint image obtained from the human
being.
10. The apparatus of claim 1, wherein the object directly makes
contact with the transparent substrate.
11. An image recognition apparatus comprising: a plurality of
sensing signal output lines disposed on a transparent substrate,
extended in a first direction and arranged in a second direction
substantially perpendicular to the first direction; a plurality of
gate lines disposed on the transparent substrate, extended in the
second direction and arranged in the first direction; a plurality
of pixel areas defined by two sensing signal output lines adjacent
to each other and two gate lines adjacent to each other; a first
recognition section formed on the pixel areas positioned at a
center portion of the transparent substrate, the first recognition
section receiving an image pattern from an object that makes
contact with the transparent substrate and generating a first
recognition signal; a bias line extended in the first direction,
arranged in the second direction and adjacent to the sensing signal
output lines, the bias line applying a predetermined voltage signal
to the first recognition section; a gate-off line extended in the
second direction, arranged in the first direction and adjacent to
the gate lines, the gate-off line outputting a gate-off signal to
the first recognition section; and a second recognition section
formed on the pixel areas adjacent to the first recognition
section, the second recognition section sensing a biological signal
from the object so as to check whether or not the first recognition
signal is obtained from a human being.
12. The apparatus of claim 11, wherein the first recognition
section comprises an image recognition sensor that generates the
first recognition signal corresponding to an amount of a reflecting
light reflected from the image pattern, the amount of the
reflecting light being differently reflected according to a
position from which the reflecting light is reflected.
13. The apparatus of claim 12, wherein the first recognition
section comprises: a sensing TFT that outputs a voltage signal
corresponding to the reflecting light reflected from the image
pattern; a storage capacitor that charges an electron charge
corresponding to the voltage signal input from the sensing TFT; and
a switching TFT that outputs a voltage signal corresponding to the
electron charge charged into the storage capacitor in response to a
switching signal applied from an external.
14. The apparatus of claim 13, wherein the sensing TFT comprises: a
drain electrode connected to the bias line; a gate electrode
connected to the gate-off line; and a source electrode connected to
the storage capacitor.
15. The apparatus of claim 13, wherein the switching TFT comprises:
a gate electrode connected to an adjacent gate line; a drain
electrode connected to an adjacent sensing signal output line; and
a source electrode connected to the storage capacitor.
16. The apparatus of claim 11, wherein the second recognition
section comprises: a first biological-signal recognition sensor
disposed on a first end portion of the transparent substrate; and a
second biological-signal recognition sensor disposed on a second
end portion of the transparent substrate, which is opposite to the
first end portion.
17. The apparatus of claim 16, wherein the first and second
biological-signal recognition sensors comprise a capacitance type
biological-signal recognition sensor that acts as a capacitor with
the object having the image pattern.
18. The apparatus of claim 17, wherein the first and second
biological-signal recognition sensors act as a lower electrode of
the capacitor and the object having the image pattern acts as a
upper electrode of the capacitor.
19. The apparatus of claim 17, wherein the biological-signal
recognition sensor comprises: a first TFT that outputs a
predetermined voltage signal; a conductive sensing electrode that
acts as the capacitor with the upper electrode, the conductive
sensing electrode charging an electron charge corresponding to the
predetermined voltage signal from the first TFT; and a second TFT
that outputs a voltage signal corresponding to the electron charge
charged into the conductive sensing electrode.
20. The apparatus of claim 19, wherein the first TFT comprises: a
gate electrode connected to an adjacent gate line; a drain
electrode commonly connected to the gate line with the gate
electrode; and a source electrode connected to the conductive
sensing electrode.
21. The apparatus of claim 19, wherein the second TFT comprises: a
gate electrode connected to an adjacent gate line; a drain
electrode connected to the sensing signal output line; and a source
electrode connected to the conductive sensing electrode.
22. The apparatus of claim 11, wherein the image pattern of the
object comprises a fingerprint image obtained from the human being.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application relies for priority upon Korean Patent
Application No. 2003-26247 filed on Apr. 25, 2003, the contents of
which are herein incorporated by reference in its entirety.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to an apparatus for
recognizing an image, and more particularly to an apparatus for
recognizing an image, capable of recognizing an image pattern from
a human being with high accuracy.
[0004] 2. Description of the Related Art
[0005] An amorphous-silicon thin film transistor liquid crystal
display apparatus (a-Si TFT-LCD apparatus), which is a kind of flat
panel display, is widely applied to an electronic instrument, for
example, such as a notebook computer, a monitor, a television set,
a mobile communication system, a hand-held electronic appliance and
so on.
[0006] Also, since the a-Si TFT-LCD, generally, includes a
photosensitive material that is chemically changeable in response
to a light, the a-Si TFT-LCD may be broadly used to biometrics
industries as a photoelectric sensor.
[0007] The biometrics industries relate to a personal verification
system using inherent biological properties, for example, such as a
fingerprint, a voice, a facial feature, a hand or an eye iris. In
view of cost, convenience and accuracy, a personal verification
system using the fingerprint among the inherent biological
properties is widely used.
[0008] A conventional fingerprint recognition apparatus includes a
photoelectric sensor, for example, such as a sensing TFT, a
switching TFT, a storage capacitor, or the like.
[0009] An operation mechanism for carrying out recognition of the
fingerprint recognition apparatus using the photoelectric sensor is
as follows.
[0010] The sensing TFT receives a light emitted from a light source
and reflected corresponding to a fingerprint image printed on a
human finger. When the sensing TFT is turned on in response to the
light, the storage capacitor charges an electron charge in
proportion to an amount of the light received into the sensing TFT.
The amount of the light received into the sensing TFT may be
different according to a position from which the light is reflected
because a reflectance between a light reflected from a ridge
portion that is protruded portion of the human finger and a light
reflected from a valley portion that is recessed portion of the
human finger is different from each other. Thus, the amount of the
electron charge charged into the sensing TFT may be varied due to
the amount of the reflected light from the fingerprint image.
[0011] The switching TFT reads out the amount of the electron
charge charged into the storage capacitor and outputs a signal
corresponding to the amount of the electron charge through a
sensing signal output line to an external.
[0012] As described above, the conventional fingerprint recognition
apparatus may recognize the fingerprint image based on the
reflected light from the fingerprint image of the human finger
while the human finger does not directly make contact with the
fingerprint recognition apparatus. Also, even if an object having
the fingerprint image is not the human finger, the conventional
fingerprint recognition apparatus recognizes the fingerprint image
as a biological signal, for example, such as the fingerprint of the
human finger, when the object makes contact with the fingerprint
recognition apparatus.
[0013] That is, although the fingerprint image printed on an
object, for example, such as a paper or the like, makes contact
with the fingerprint recognition apparatus, the fingerprint
recognition apparatus recognizes the fingerprint image printed on
the object as a normal biological signal from the human finger. As
a result, an accuracy of the fingerprint recognition apparatus for
verifying a normal user may be lowered.
BRIEF SUMMARY OF THE INVENTION
[0014] The present invention provides an image recognizing
apparatus capable of recognizing an image with high accuracy.
[0015] In one aspect of the invention, an image recognizing
apparatus includes a transparent substrate, a first recognition
section disposed on the transparent substrate, and a second
recognition section disposed on the transparent substrate adjacent
to the first recognition section.
[0016] The first recognition section receives an image pattern from
an object and generates a first recognition signal corresponding to
the received image pattern, and the second recognition section
senses a biological signal from the object so as to check whether
or not the first recognition signal is obtained from a human
being.
[0017] The first recognition section may include an image
recognition sensor for generating the first recognition signal
corresponding to an amount of a reflecting light reflected from the
image pattern. The amount of the reflecting light may be
differently reflected according to a position from which the
reflecting light is reflected.
[0018] The second recognition section may include a capacitance
type biological-signal recognition sensor operated as a capacitor
with the object having the image pattern.
[0019] The image pattern of the object may include a fingerprint
image obtained from the human being, and the object may generally
and directly makes contact with the transparent substrate.
[0020] In another aspect of the invention, an image recognizing
apparatus includes a plurality of sensing signal output line
disposed on a transparent substrate, extended in a first direction
and arranged in a second direction substantially perpendicular to
the first direction, a plurality of gate line disposed on the
transparent substrate, extended in the second direction and
arranged in the first direction, a plurality of pixel areas defined
by two sensing signal output lines adjacent to each other and two
gate lines adjacent to each other, a first recognition section
formed on the pixel areas positioned at a center portion of the
transparent substrate, a bias line extended in the first direction,
arranged in the second direction and adjacent to the sensing signal
output lines, a gate-off line extended in the second direction,
arranged in the first direction and adjacent to the gate lines, and
a second recognition section formed on the pixel areas adjacent to
the first recognition section.
[0021] The first recognition section receives an image pattern from
an object that makes contact with the transparent substrate and
generates a first recognition signal and the bias line applies a
predetermined voltage to the first recognition section. The
gate-off line outputs a gate-off signal to the first recognition
section and the second recognition section senses a biological
signal from the object so as to check whether or not the first
recognition signal is obtained from a human being.
[0022] The image pattern of the object may comprise a fingerprint
image obtained from the human being, and the object may generally
and directly makes contact with the transparent substrate.
[0023] Accordingly, the image recognition apparatus may check that
whether or not the image pattern, for example, such as a
fingerprint image, is obtained from the human being, thereby
recognizing the image pattern with high accuracy and improving
reliability thereof.
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] The above and other advantages of the present invention will
become readily apparent by reference to the following detailed
description when considered in conjunction with the accompanying
drawings wherein:
[0025] FIG. 1 is a schematic view showing a fingerprint recognition
apparatus according to an exemplary embodiment of the present
invention;
[0026] FIG. 2 is a circuit diagram showing the fingerprint
recognition apparatus shown in FIG. 1;
[0027] FIG. 3 is a schematic view showing a portion "A" shown in
FIG. 2;
[0028] FIG. 4 is a cross-sectional view taken along the line B-B'
for showing the fingerprint recognition apparatus shown in FIG.
3;
[0029] FIG. 5 is a cross-sectional view taken along the line C-C'
for showing the fingerprint recognition apparatus shown in FIG.
3;
[0030] FIG. 6 is a schematic view illustrating operations for
recognition of fingerprint image and biological-signal between the
human finger and fingerprint recognition apparatus;
[0031] FIGS. 7A to 7C are views illustrating a method of
fabricating a biological-signal recognition sensor of a fingerprint
recognition apparatus according to an exemplary embodiment of the
present invention; and
[0032] FIG. 8 is a cross-sectional view illustrating a method of
fabricating a fingerprint recognition sensor of a fingerprint
recognition apparatus according to an exemplary embodiment of the
present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0033] Hereinafter, an apparatus for recognizing an image pattern,
for example, such as a fingerprint image from an object, will be
described.
[0034] Particularly, in this exemplary embodiment, a fingerprint
recognition apparatus that recognizes an image pattern, for
example, such as the fingerprint image from a human being, will be
described. That is, the object having the image pattern may
comprise at least the fingerprint image of the human being.
[0035] FIG. 1 is a schematic view showing a fingerprint recognition
apparatus according to an exemplary embodiment of the present
invention. FIG. 2 is a circuit diagram showing the fingerprint
recognition apparatus shown in FIG. 1.
[0036] Referring to FIG. 1, a fingerprint recognition apparatus 100
includes a fingerprint recognition area 110 for receiving a
fingerprint image from the object and generating a fingerprint
recognition signal corresponding to the fingerprint image, a first
biological-signal recognition area 120a and a second
biological-signal recognition area 120b for sensing a biological
signal from the object so as to check that whether or not the
fingerprint recognition signal generated from the fingerprint
recognition area 110 is obtained from the human being.
[0037] The fingerprint recognition area 110 is formed on a center
portion of the fingerprint recognition apparatus 100 and the first
and second biological-signal recognition areas 120a and 120b are
formed on a peripheral portion of the fingerprint recognition
apparatus 100. That is, the first and second biological-signal
recognition areas 120a and 120b are formed adjacent to a first end
of the fingerprint recognition apparatus 100 and a second end
opposite to the first end thereof, respectively.
[0038] When the first and second biological-signal recognition
areas 120a and 120b are disposed on the first and second ends,
respectively, a fingerprint image recognized through the
fingerprint recognition area 110 may be normally verified by means
of the first and second biological-signal recognition areas 120a
and 120b.
[0039] Also, by disposing the first and second biological-signal
recognition areas 120a and 120b as shown in FIG. 1, the biological
signal, which is representing that whether or not the object having
the fingerprint image is human being, may be easily sensed through
one of the first and second biological-signal recognition areas
120a and 120b although a human finger of the human being makes
contact with the fingerprint recognition area 110.
[0040] The fingerprint recognition area 110 includes a plurality of
fingerprint recognition sensors that recognizes the fingerprint
image using a photocurrent, and the first and second
biological-signal recognition areas 120a and 120b include a
plurality of biological-signal recognition sensors that senses the
biological signal from the object using a capacitance.
[0041] Referring to FIG. 2, the biological-signal recognition
sensor having a first TFT 210, a second TFT 220 and a conductive
sensing electrode 230 is formed on the first biological-signal
recognition area 120a in a matrix configuration. The conductive
sensing electrode 230 acts as a capacitor with the human finger
that makes contact with an upper surface of the fingerprint
recognition apparatus 100. That is, the conductive sensing
electrode 230 and human finger act as a lower electrode and a upper
electrode of the capacitor, respectively.
[0042] Source electrodes S1 and S2 of the first and second TFTs 210
and 220 are electrically connected to each other by means of the
conductive sensing electrode 230. The first TFT 210 includes a gate
electrode G1 connected to a first gate-on line Gate_on (1) and a
drain electrode D1 commonly connected to the first gate-on line
Gate_on (1) with the gate electrode G1 thereof. The second TFT 220
includes a gate electrode G2 connected to a second gate-on line
Gate_on (2) and a drain electrode D2 connected to a first sensing
signal output line Readout(1).
[0043] The fingerprint recognition sensor having a third TFT 240, a
fourth TFT 250 and a storage capacitor Cst is formed on the
fingerprint recognition area 110 in a matrix configuration. The
third and fourth TFTs 240 and 250 are operated as a sensing TFT and
a switching TFT, respectively.
[0044] As shown in FIG. 2, the second biological-signal recognition
area 120b includes same elements and function as in those of the
first biological-signal recognition area 120a, and thus the
detailed descriptions of the same elements will be omitted.
[0045] The third TFT 240 includes a drain electrode D3 connected to
a first power line V.sub.DD1, a source electrode S3 connected to
the storage capacitor Cst and a gate electrode G3 connected to a
first gate-off line Gate_off (1). The fourth TFT 250 includes a
source electrode S4 commonly connected to the storage capacitor Cst
with the source electrode S3 of the third TFT 240, a drain
electrode D4 connected to the first sensing signal output line
Readout (1) and a gate electrode G4 connected to the second gate-on
line Gate_on (2).
[0046] The biological-signal recognition sensor formed on the first
biological-signal recognition area 120a is connected to the first
and second gate-on lines Gate_on (1) and Gate_on (2) positioned at
a first end of the fingerprint recognition apparatus 100. Also, the
biological-signal recognition sensor formed on the second
biological-signal recognition area 120b is connected to the Nth and
(N-1)-th gate-on lines Gate_on (N) and Gate_on (N-1) positioned at
a second end of the fingerprint recognition apparatus 100.
[0047] In FIG. 2, the biological-signal recognition sensor formed
in one row at the first and second ends of the fingerprint
recognition area 110, respectively, has been described. However,
the biological-signal recognition sensor may be formed in a
plurality of rows at the first and second ends thereof.
[0048] FIG. 3 is a schematic view showing a portion "A" shown in
FIG. 2. FIG. 4 is a cross-sectional view taken along the line B-B'
for showing the fingerprint recognition apparatus shown in FIG. 3.
FIG. 5 is a cross-sectional view taken along the line C-C' for
showing the fingerprint recognition apparatus shown in FIG. 3. FIG.
6 is a schematic view illustrating operations for recognition of
fingerprint image and biological-signal between the human finger
and fingerprint recognition apparatus.
[0049] Referring to FIGS. 3 and 4, the first TFT 210 includes a
first channel area 306 formed between the source and drain
electrodes 302 and 304 and the second TFT 220 includes a second
channel area 316 formed between the source and drain electrodes 312
and 314. The first and second channel areas 306 and 316 have an
a-Si. In order to insulate the source electrodes 302 and 312 and
the drain electrodes 304 and 314, a gate insulating layer 320 is
formed over the transparent substrate 300 on which the gate
electrodes 308 and 318 of the first and second TFTs 210 and 220 are
formed.
[0050] The conductive sensing electrode 230 is formed on the gate
insulating layer 320 so as to electrically connect the source
electrode of the first TFT 210 and the source electrode 312 of the
second TFT 220. A protecting layer 330 is formed over the
transparent substrate 300 on which the conductive sensing electrode
230 and the first and second TFTs 210 and 220 are formed. Thus, in
case that the human finger 340 makes contact with an upper surface
of the biological-signal recognition sensor, the conductive sensing
electrode 230 and human finger 340 may act as the lower electrode
and upper electrode of the capacitor, respectively, with the
protecting layer 330 formed between the conductive sensing
electrode 230 and the human finger 340. That is, an electron charge
is charged between the conductive sensing electrode 230 and human
finger 340 corresponding to a voltage applied through the first TFT
210.
[0051] In the biological-signal recognition sensor, the first TFT
210 is turned on in response to a gate-on signal input through the
first gate-on line Gate_on (1) to apply a voltage corresponding to
the gate-on signal to the conductive sensing electrode 230. The
capacitor using the conductive sensing electrode 230 and human
finger 340 charges the electron charge corresponding to the voltage
provided from the first TFT 210. The second TFT 220 is turned on in
response to a gate-on signal input through the second gate-on line
Gate_on (2) to output a voltage signal through the first sensing
signal output line Readout (1), which is corresponding to the
electron charge charged between the conductive sensing electrode
230 and human finger 340. The voltage signal output from the first
sensing signal output line Readout (1) is a biological-signal
sensing signal.
[0052] As shown in FIGS. 3 and 5, the third TFT 240 includes a
third channel area 406 formed between the source and drain
electrodes 402 and 404 thereof and the fourth TFT 250 includes a
fourth channel area 416 formed between the source and drain
electrodes 412 and 414 thereof. The third and fourth channel areas
406 and 416 have the a-Si. When a light having a predetermined
amount is supplied to the third channel area 406, the third channel
area 406 formed between the source and drain electrodes 402 and 404
of the third TFT 240 is electrically turned on.
[0053] The source electrode 402 of the third TFT 240 is
electrically connected to the source electrode 412 of the fourth
TFT 250 by means of a first electrode 420 operated as the lower
electrode of the storage capacitor Cst. An insulating layer 430 is
formed over the transparent substrate 300 on which the first
electrode 420 is formed. A second electrode 440 operated as the
upper electrode of the storage capacitor Cst is formed on the
insulating layer 430 corresponding to the first electrode 420. That
is, the storage capacitor Cst includes the first electrode 420,
second electrode 440 and insulating layer 430 and charges the
electron charge in proportion to an amount of the light supplied to
the third TFT 240.
[0054] In order to insulate the source electrodes 402 and 412 and
drain electrodes 404 and 414 of the third and fourth TFTs 240 and
250, a gate insulating layer 450 is formed on the gate electrodes
408 and 418 of the third and fourth TFTs 240 and 250. A shielding
layer 460 is formed on the source and drain electrodes 412 and 414
of the fourth TFT 250 so as to shield the light, which is incident
thereon. A protecting layer 470 is formed over the transparent
substrate 300 on which the shielding layer 460 is formed.
[0055] When a reflecting light reflected from the fingerprint image
of the human finger 340 that makes contact with the fingerprint
recognition apparatus 100 is supplied to the third channel area 406
of the third TFT 240, the third TFT 240 is turned on. The third TFT
240 applies to a voltage signal to the storage capacitor Cst, which
is corresponding to the reflecting light supplied to the third
channel area 406 of the third TFT 240.
[0056] The fingerprint image includes a raised ridge portion and a
recessed valley portion having a light reflectance different to
each other. Thus, the voltage signal applied from the third TFT 240
to the storage capacitor Cst has a different level each other in
accordance with the raised ridge portion and the recessed valley
portion.
[0057] The storage capacitor Cst charges the electron charge
corresponding to the voltage signal output from the third TFT 240.
The fourth TFT 250 is turned on in response to the gate-on signal
output through the second gate-on line Gate_on (2) and outputs a
voltage signal corresponding to the electron charge charged into
the storage capacitor Cst through the first sensing signal output
line Readout (1). The voltage signal output from the first sensing
signal output line Readout (1) is a fingerprint image signal.
[0058] Hereinafter, the fingerprint recognition apparatus according
to the exemplary embodiment of the present invention will be
described.
[0059] The drain electrode 404 of the third TFT 240 receives a
direct current voltage V.sub.DD having a predetermined voltage
level and gate electrode 408 thereof receives a predetermined bias
voltage.
[0060] The fourth TFT 250 is switched in response to a gate driving
signal generated from a gate driving section (not shown) and
applied through the gate electrode 418 connected to the second
gate-on line Gate_on (2). In order to switch the fourth TFT 250,
the gate driving section (not shown) outputs the gate driving
signal corresponding to every frame for scanning the fingerprint
image. Thus, the fingerprint image of the human finger 340 that
makes contact with the fingerprint recognition apparatus 100 may be
scanned corresponding to every frame of the fingerprint recognition
sensors arranged in a matrix configuration.
[0061] The drain electrode 414 of the fourth TFT 250 is connected
to an amplifying section (not shown) of a data reading-out section
(not shown) through the first sensing signal output line Readout
(1). When the fourth TFT 250 is turned on, the voltage signal in
proportion to the electron charge charged into the storage
capacitor Cst is outputted through the first sensing signal output
line Readout (1) as a first recognition signal (hereinafter,
referred to as a fingerprint recognition signal).
[0062] The first TFT 210 of the first biological-signal recognition
area 120a is switched in response to the gate-on signal applied
from the gate driving section (not shown) and applies a voltage
signal corresponding to the gate-on signal to the conductive
sensing electrode 230. The gate-on signal from the gate driving
section is applied to the first TFT 210 through the gate electrode
308 connected to the first gate-on line Gate_on (1).
[0063] The conductive sensing electrode 230, as shown in FIG. 6,
acts as the capacitor with the human finger 340 that partially
makes contact with the first biological-signal recognition area
120a and charges the electron charge corresponding to the voltage
signal from the first TFT 210. The second TFT 220 is switched in
response to the gate-on signal applied from the gate driving
section (not shown) and outputs a voltage signal corresponding to
the electron charge charged into the conductive sensing electrode
230 through the first sensing signal output line Readout (1). The
gate-on signal from the gate driving section is applied to the
second TFT 220 through the gate electrode 318 connected to the
second gate-on line Gate_on (2).
[0064] As described above, when the biological-signal sensing
signal is outputted from the biological-signal recognition sensor,
the fingerprint recognition apparatus 100 may check that whether or
not the fingerprint recognition signal recognized by the
fingerprint recognition sensor is obtained from the human finger
340 of the human being.
[0065] As a result of the check, if the biological-signal sensing
signal is not outputted from the biological-signal recognition
sensor 200, the fingerprint recognition apparatus 100 may judge
that the fingerprint recognition signal recognized by the
fingerprint recognition sensor is not obtained from the human
being.
[0066] Hereinafter, a method of fabricating the fingerprint
recognition apparatus according to an exemplary embodiment of the
present invention will be described with reference to accompanying
drawings.
[0067] FIGS. 7A to 7C are views illustrating a method of
fabricating the biological-signal recognition sensor of the
fingerprint recognition apparatus according to an exemplary
embodiment of the present invention.
[0068] Referring to FIG. 7A, a first metal layer (not shown)
including aluminum (Al), chromium (Cr) or molybdenum-tungsten (MoW)
is deposited on the transparent substrate 300 including glass,
quartz or sapphire by a sputtering method. The first metal layer is
patterned to form the gate electrodes 308 and 318 of the first and
second TFTs 210 and 220.
[0069] The gate insulating layer 320 including silicon nitride
(SiNx) is formed over the transparent substrate 300, on which the
gate electrodes 308 and 318 are formed, by a PECVD (Plasma-Enhanced
Chemical Vapor Deposition) method.
[0070] An amorphous silicon layer and an n+amorphous silicon layer
are deposited on the gate insulating layer 320 by the PECVD method
and patterned to form the first and second channel areas 306 and
316.
[0071] Referring to FIG. 7B, a second metal layer (not shown)
including chromium is deposited over the transparent substrate 300
by the sputtering method. The second metal layer is patterned to
form the source and drain electrodes 302 and 304 of the first TFT
210 and the source and drain electrodes 312 and 314 of the second
TFT 220.
[0072] Referring to FIG. 7C, indium tin oxide is deposited over the
transparent substrate 300 on which the first and second TFTs 210
and 220 are formed. The indium tin oxide is patterned to form the
conductive sensing electrode 230. The conductive sensing electrode
230 electrically connects the source electrode 302 of the first TFT
210 and the source electrode 312 of the second TFT 220.
[0073] The protecting layer 330 (see FIG. 4) is formed over the
transparent substrate 300 on which the conductive sensing electrode
230 is formed, thereby completing the biological-signal recognition
sensor as shown in FIG. 4.
[0074] FIG. 8 is a cross-sectional view illustrating a method of
fabricating a fingerprint recognition sensor of a fingerprint
recognition apparatus according to an exemplary embodiment of the
present invention.
[0075] Referring to FIG. 8, the third and fourth TFTs 240 and 250
are formed on the transparent substrate 300 through processes same
as in those for forming the first and second TFTs 210 and 220.
Also, the first electrode 420 is formed on the transparent
substrate 300 to electrically connect the source electrode 402 of
the third TFT 240 to the source electrode 412 of the fourth TFT
250.
[0076] The insulating layer 430 including the silicon nitride is
formed over the transparent substrate 300 on which the first
electrode 420 is formed. The indium tin oxide is deposited on the
insulating layer 430 and patterned to form the second electrode 440
corresponding to the first electrode 420. Thus, the storage
capacitor Cst includes the first electrode 420, second electrode
440 and insulating layer 430. The first and second electrodes 420
and 440 act as the lower and upper substrates of the storage
capacitor Cst, respectively.
[0077] The shielding layer 460 is formed on the insulating layer
430 corresponding to the fourth channel area 416 of the fourth TFT
250 by depositing chromium/chromium oxide (Cr/CrxOy) and patterning
the chromium/chromium oxide (Cr/CrxOy). The protecting layer 470
(see FIG. 5) is formed over the transparent substrate 300 on which
the shielding layer 460 is formed, thereby completing the
fingerprint recognition sensor as shown in FIG. 5
[0078] The protecting layer 470 (see FIG. 5) formed over the third
and fourth TFTs 240 and 250 is formed by same material and process
as in those of the protecting layer 330 (see FIG. 4) formed over
the first and second TFTs 210 and 220.
[0079] According to the present invention described above, the
fingerprint recognition apparatus includes the fingerprint
recognition sensor that recognizes the fingerprint image from the
human finger using the photoelectric type sensor and the
biological-signal recognition sensor that recognizes the biological
signal from the human finger using the capacitance type sensor.
[0080] Thus, the fingerprint recognition apparatus may check that
whether or not the fingerprint recognition signal recognized by the
fingerprint recognition sensor is obtained from the human being
with the biological-signal recognition sensor, to thereby recognize
the fingerprint with high accuracy and improve reliability
thereof.
[0081] In addition, no substrate is separately needed to form the
biological-signal recognition sensor on the fingerprint recognition
apparatus because the biological-signal recognition sensor and
fingerprint recognition sensor may be formed on one transparent
substrate as one array circuit, thereby improving a light
transmittance of the fingerprint recognition apparatus.
[0082] Although the exemplary embodiments of the present invention
have been described, it is understood that the present invention
should not be limited to these exemplary embodiments but various
changes and modifications can be made by one ordinary skilled in
the art within the spirit and scope of the present invention as
hereinafter claimed.
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